Device for attaching index-fingers to arbors.



PATENTED JUNE 30, 1908.

A. WIRSGH-ING. DEVICE FOR ATTACHING INDEX FINGERS T0 ARBORS.

APPLIOATION FILED MAB-.11, 1908.

ALOYS WIRSOHING, OF BROOKLYN, NEW-YORK.

DEVICE FOR ATTACHING INDEX-FINGERS TO ARBORS.

Specification of Letters Patent.

Patented June so, 1908.

Application filed March 11, 1908. Serial No. 420,370.

T 0 all whom it may concern:

Be it known that I, ALoYs I/VIRSGHING, a citizen of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented a certain new and useful Improvement in Devices for Attaching Index-Fingers to Arbors, of which the following is a specification.

The invention relates to the attachment of index fingers to arbors and consists in the device hereinafter set forth, whereby said attachment may be effected without the use of pins, screws, or any parts additional to the arbor and index finger to be connected.

The invention is applicable to all apparatus wherein moving index fingers are employed, such as clocks, and especially the minute hands thereof, gages, registers, and measuring instruments of all kinds.

In the accompanying drawings-Figure 1 shows part of a dial, the index fingers thereon and supporting arbor. Fig. 2 is an end view of the arbor. Fig. 3 is an enlarged side elevation of the arbor with the index finger in place thereon. Fig. 4 is a section on the line a; :1; of Fig. 3.

Similar letters of reference indicate like partss The arbor A which may be vibrated. or rotated in any suitable way has, near its end, a shoulder B. The end portion 0 of said arbor beyond said shoulder is polygonal and preferably rectangular, in cross section, as shown. Adjacent to the shoulder said portion C is of contracted cross-sectional area and may be provided with a peripheral groove D. It is also bifurcated, the bifurcations being separated by a wedge shaped recess E, preferably symmetrically placed and terminating in a transverse hole F. A portion of the metal of the arbor, on each side and opposite the hole F may be cut away as shown at G.

H is an index finger formed in the usual way of thin metal and having at one end an enlarged portion I, in which'is a polygonal opening corresponding in shape to the cross section of the polygonal portion C of arbor A, but about equal in area to a cross section taken through the groove D on the line a; as Fig. 3, and hence somewhat less in area than a cross section of the portion C beyond said groove.

In order to attach the index finger to the arbor, the bifurcations of the arbor are pinched together by the hand of the operator, so that the portion C can be inserted in the opening in the finger as shown in Fig. 3. The finger plate I is then received in the groove D, and rests on shoulder B. The bifurcations being released spring back to normal position and the finger is thus firmly retained in place in the groove D. The finger is thus prevented from coming oil the arbor, unless the parts of said arbor are brought together by the hand of an operator, as before.

The object of the hole F and the cut away portions G is to make the bifurcations of the arbor more elastic and yielding.

I claim:

1. In combination with an index finger having a polygonal opening, an arbor having a bifurcated end of corresponding cross section to said opening: the said bifurcated portion having a peripheral groove and constructed to enter said finger opening when said bifurcations are approximated: and the said finger being thereafter retained in said groove solely by the resilient return of said bifurcations to normal position.

2. In combination with an index finger having a polygonal opening, an arbor having an integrally formed shoulder and a bifurcated portion beyond said shoulder of corresponding cross section to said opening: the said end portion being of contracted cross sectional area immediately adjacent to said shoulder and being constructed to enter said finger opening when the bifurcations are approximated: and the said finger being thereafter retained on said shoulder solely by the resilient return of said bifurcations to normal position.

3. In combination with an index finger having a polygonal opening, an arbor having an integrally formed shoulder and a bifurcated end portion beyond said shoulder of corresilient return of said bifurcations to normal responding cross section to said opening: the position. 10 said end portion having a peripheral groove In testimony whereof I have afiixed my adjacent to said shoulder and being oonsignature in presence of tWo Witnesses.

5 structed to enter said finger opening, when ALOYS WIRSCHING.

the bifurcations are approximated: and the Witnesses: said finger being thereafter retained in said GERTRUDE T. PORTER,

groove and on said shoulder solely by the RICHARD W. UHLIG. 

